In a known conventional structure, a plurality of photoelectric conversion layers are laminated in order to improve the photoelectric conversion efficiency of a thin-film solar cell (photoelectric conversion device). For example, in a known tandem solar cell, an amorphous silicon layer and a microcrystalline silicon layer are laminated. This tandem solar cell is manufactured when thin films, such as a transparent electrode, the amorphous silicon layer, the microcrystalline silicon layer, and a back electrode, are sequentially laminated on a light transmissive substrate. There is a known technology for further improving the photoelectric conversion efficiency, in which an electrically and optically connected intermediate contact layer (thin film) is provided between the amorphous silicon layer and the microcrystalline silicon layer to reflect part of incident light.
In this tandem solar cell, a plurality of photoelectric conversion cells are serially connected to achieve higher voltage to obtain a desired voltage. When the plurality of photoelectric conversion cells are serially connected, a connecting groove that passes through the amorphous silicon layer, the intermediate contact layer, and the microcrystalline silicon layer is formed and is filled with the back electrode, thereby connecting the back electrode and the transparent electrode.
On the other hand, since the intermediate contact layer has electrical conductivity, when it is electrically connected to the connecting groove filled with the back electrode, current produced in the amorphous silicon layer or the microcrystalline silicon layer leaks into the connecting groove via the intermediate contact layer.
Thus, various technologies have been proposed to prevent current leakage from the intermediate contact layer to the connecting groove by separating the intermediate contact layer through laser processing (see PTL 1 and PTL 2).